<template>
  <div class="com-container">
    <div class="com-chart" ref="hot_ref"></div>
    <span class="iconfont arr-left" @click="toLeft" :style="comStyle">&#xe6ef;</span>
    <span class="iconfont arr-right" @click="toRight" :style="comStyle">&#xe6ed;</span>
    <span class="cat-name" :style="comStyle">{{ catName }}</span>
  </div>
</template>

<script>
import { mapState } from 'vuex'
import { getThemeValue } from '../utils/theme_utils'
export default {
  name: "Hot",
  data() {
    return {
      chartInstance: null,
      allData: null,
       currentIndex: 0, // 当前所展示出的一级分类数据
       titleFontSize: 0
    };
  },
    computed: {
     catName () {
      if (!this.allData) {
        return ''
      } else {
        return this.allData[this.currentIndex].name
      }
    },
    comStyle () {
      return {
        fontSize: this.titleFontSize + 'px',
        color: getThemeValue(this.theme).titleColor
      }
    },
       ...mapState(['theme'])
    
    
  },
  created() {
    this.$socket.registerCallBack('hotData', this.getData)
  },
  mounted() {
    this.initChart();
    //this.getData();
     this.$socket.send({
      action: 'getData',
      socketType: 'hotData',
      chartName: 'hotproduct',
      value: '',
    })
    window.addEventListener("resize", this.screenAdapter);
    //屏幕自适配
    this.screenAdapter();
  },
  destroyed() {
    window.removeEventListener("resize", this.screenAdapter);
     this.$socket.unRegisterCallBack('hotData')
  },
  methods: {
    initChart() {
      this.chartInstance = this.$echarts.init(this.$refs.hot_ref, this.theme);
      //对图表初始化配置的控制
      const initOption = {
           title: {
          text: '▎ 热销商品的占比',
          left: 20,
          top: 20
        },
        legend: {
          top: '15%',
          icon: 'circle'
        },
        tooltip: {
          show: true,
          formatter: arg => {
            // console.log(arg)
            const thirdCategory = arg.data.children
            //console.log(thirdCategory);
            // 计算出所有三级分类的数值总和
            let total = 0
            thirdCategory.forEach(item => {
              total += item.value
            })
            let retStr = ''
            thirdCategory.forEach(item => {
              retStr += `
              ${item.name}:${parseInt(item.value / total * 100) + '%'}
              <br/>
              `
            })
            return retStr
          }
        },
             series: [
          {
            type: 'pie',
            label: {
              show: false
            },
            emphasis: {
              label: {
                show: true
              },
              labelLine: {
                show: false
              }
            }
          }
             ]
      };
      this.chartInstance.setOption(initOption);
    },
     getData(ret) {
      //const { data: ret } = await this.$http.get("hotproduct");
      this.allData = ret;
     // console.log(this.allData);
      this.updateChart();
    },
    updateChart() {
      // 处理图表需要的数据
      const legendData = this.allData[this.currentIndex].children.map(
        (item) => {
          return item.name;
        }
      );
      const seriesData = this.allData[this.currentIndex].children.map(
        (item) => {
          return {
            name: item.name,
            value: item.value,
            children: item.children // 新增加children的原因是为了在tooltip中的formatter的回调函数中,来拿到这个二级分类下的三级分类数据
          };
        }
      );
      const dataOption = {
        legend: {
          data: legendData,
        },
        series: [
          {
            data: seriesData,
          },
        ],
      };
      this.chartInstance.setOption(dataOption);
    },
    screenAdapter() {
        this.titleFontSize = this.$refs.hot_ref.offsetWidth / 100 * 3.6
      const adapterOption = {
          title: {
          textStyle: {
            fontSize: this.titleFontSize
          }
        },
        legend: {
          itemWidth: this.titleFontSize,
          itemHeight: this.titleFontSize,
          itemGap: this.titleFontSize / 2,
          textStyle: {
            fontSize: this.titleFontSize / 2
          }
        },
        series: [
          {
            radius: this.titleFontSize * 4.5,
            center: ['50%', '60%']
          }
        ]
      };
      this.chartInstance.setOption(adapterOption);
      this.chartInstance.resize();
    },
        toLeft () {
      this.currentIndex--
      if (this.currentIndex < 0) {
        this.currentIndex = this.allData.length - 1
      }
      this.updateChart()
    },
    toRight () {
      this.currentIndex++
      if (this.currentIndex > this.allData.length - 1) {
        this.currentIndex = 0
      }
      this.updateChart()
    }
  },
  watch: {
    theme () {
      console.log('主题切换了')
      this.chartInstance.dispose() // 销毁当前的图表
      this.initChart() // 重新以最新的主题名称初始化图表对象
      this.screenAdapter() // 完成屏幕的适配
      this.updateChart() // 更新图表的展示
    }
  }
};
</script>

<style lang="less" scoped>
.arr-left {
  position:absolute;
  left: 10%;
  top: 50%;
  transform: translateY(-50%);
  cursor: pointer;
  color: white;
}
.arr-right {
  position:absolute;
  right: 10%;
  top: 50%;
  transform: translateY(-50%);
  cursor: pointer;
  color: white;
}
.cat-name {
  position:absolute;
  left: 80%;
  bottom: 20px;
  color: white;
}
</style>